Study on the CCM breakdown voltage of proton exchange membrane fuel cells

Abstract

Proton exchange membrane (PEM) short circuits are one of the failure forms of fuel cells. In this paper, the change in breakdown voltage (BV) after the preparation of PEMs into catalyst coated membranes (CCMs) is studied, and the impact of the catalyst layer (CL) and its composition on the BV of the CCM is analysed. The results show that the BV of the CCM is significantly lower than that of the uncoated PEM. The higher the platinum (Pt) loading of the coated CL is, the lower the BV. Further research finds that the BV of the single-side CL-coated CCM only decreases when the CL side is connected to the positive pole of the power supply, while it is comparable to that of the PEM when the CL side is connected to the negative pole. The experimental results demonstrate that the Pt and carbon particles in the CCM undergo electrochemical reactions during the breakdown process when the CL is connected to the positive pole, which eventually leads to thermal breakdown. Therefore, when the BV is chosen for detecting whether the CCM preparation process causes PEM damage, single-side CL-coated CCM should be adopted, and the CL should be connected to the negative pole of the power supply.